What's New
Undo
An Undo button now sits below the board, and Ctrl+Z does the same thing.
Step back one move at a time, up to 300 moves.
Auto-mark (Settings → Auto-mark, off by default)
When it's on, placing a clover automatically marks its whole row, its whole
column and the diagonal squares next to it with an ✕.
Taking that clover back clears those marks again.
Any ✕ you placed yourself is left untouched.
Hint confirmation
Pressing Hint no longer reveals an answer straight away — a confirmation
appears first, so a stray click costs you nothing.
Choosing "Not now" does not use up a hint.